Not disagreeing with anyone or anything, just posting this just as an FYI. I didn't search, but I'm sure there is something similar already on 'MUD somewhere.
I'm sure several people are aware of this, but For those of you wondering which ram to use, consider this - when using a single acting cylinder (single sided,) there will always be less "assist" in one direction. This is due to the difference in piston surface area on the two sides of the piston because of the surface area occupied by the shaft on one side. The larger the diameter of the shaft, the less surface area on the piston inside the cylinder (on the shaft side only.) The less surface area there is, the less effective the ram will be.
Most (but certainly not all) 1.5" bore hydro assist cylinders are built with ~3/4" and smaller shafts which greatly increases the surface area on the one side of the piston versus the same bore diameter with a 1" shaft. In my experience, a 3/4" shaft is plenty adequate strength-wise (as long as the cylinder doesn't do double duty as a skid plate or tow hook.
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The following numbers are the amount of force applied to the piston inside a 1.5" bore cylinder assuming a fluid pressure of 1200 psi (rough estimate of a typical steering system) as calculated on engineeringtoolbox.com:
Non-shaft side of piston = 2121 lbs. This number will be the same for any size shaft in a 1.5" bore, since it is on the other side of the piston. One direction of turning will have this amount of force.
Shaft side of piston with 3/4" shaft = 1590 lbs.
Shaft side of piston with 1" shaft = 1178 lbs.
You can see that even with the smaller 3/4" shaft there is still a marked difference in the force applied to the two sides of the piston, but with the 1" shaft, it is almost half the force on the shaft side.
Assume 2121 lbs of force is 100% of the available force your system will put out. That means the following:
With a 3/4" shaft you will have 100% assist turning one direction, but only ~75% in the other direction.
With a 1" shaft you will have 100% assist turning one direction, but only ~55% in the other direction.
Take this for what it's worth, and do with it as you please.
I'm sure several people are aware of this, but For those of you wondering which ram to use, consider this - when using a single acting cylinder (single sided,) there will always be less "assist" in one direction. This is due to the difference in piston surface area on the two sides of the piston because of the surface area occupied by the shaft on one side. The larger the diameter of the shaft, the less surface area on the piston inside the cylinder (on the shaft side only.) The less surface area there is, the less effective the ram will be.
Most (but certainly not all) 1.5" bore hydro assist cylinders are built with ~3/4" and smaller shafts which greatly increases the surface area on the one side of the piston versus the same bore diameter with a 1" shaft. In my experience, a 3/4" shaft is plenty adequate strength-wise (as long as the cylinder doesn't do double duty as a skid plate or tow hook.
)The following numbers are the amount of force applied to the piston inside a 1.5" bore cylinder assuming a fluid pressure of 1200 psi (rough estimate of a typical steering system) as calculated on engineeringtoolbox.com:
Non-shaft side of piston = 2121 lbs. This number will be the same for any size shaft in a 1.5" bore, since it is on the other side of the piston. One direction of turning will have this amount of force.
Shaft side of piston with 3/4" shaft = 1590 lbs.
Shaft side of piston with 1" shaft = 1178 lbs.
You can see that even with the smaller 3/4" shaft there is still a marked difference in the force applied to the two sides of the piston, but with the 1" shaft, it is almost half the force on the shaft side.
Assume 2121 lbs of force is 100% of the available force your system will put out. That means the following:
With a 3/4" shaft you will have 100% assist turning one direction, but only ~75% in the other direction.
With a 1" shaft you will have 100% assist turning one direction, but only ~55% in the other direction.
Take this for what it's worth, and do with it as you please.
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